Method and apparatus for unstacking lumber



July 10, 1928.

J. M. LEAVER. ET AL METHOD AND APPARATUS FOR UNSTACKING LUMBER Filed April '7, 192

flame u r H m. 5 a .0 mew 8 e I AM J m July 10, 1928; 1.676.957

. J'. M. LEAVER, ET AL "METHOD AND APPARATUS FOR UNSTACKING LUMBER Filed April 7, 1924 4 Sheets-Sheet 2 OPEN/N6 85 WWWHEN! [Iii and JngeJ/T. Leaver f1 I Mu W gar/71 5.

July 10, 1928.

J. M. LEAVER, ET AL METHOD AND APPARATUS FOR UNSTACKING LUMBER Filed April 1924 4 Sheets-Sheet 3 J/7U6/7ZIO/"5 Tame; Lea ver and Jame: M Leave/ J'- July 10, 1928.

J. -M. LEAVER, ET AL METHOD AND APPARATUS FOR UNSTACKING LUMBER Filed April 7, 1924 4 Sheets-Sheet jflae/ to/ts James M L a and Tamer/ 7. Leaver J1 vide a method which permits of this work done mechanically, andthe vicinity of the sorting table or chains on a drag. conveyor,

. time is picked up Patented July 10, 1928.

UNITED STATES PATENT OFFICE.

JAMES M. LEAVER AND JAMES M. LEAVEB, J'IL, OF OAKLAND, CALIFORNIA. A

METHOD, AND APPARATUS FOR UNSTACKING' LUMBER.

Application filed April 7, 1924. Serial No. 704,714.

to break down the stack, remove the boards and feed them to a sorting table.

The objects of our invention are to proof unstacking being to provide a practicable, durable association of mechanical elements for carrying out the method. i With our method the units are brought to and one complete unit at a by a set of arms, tipped over at an angle so that the boards will slide to definitely position their edges in relation toa series of moving pick up chains which pick ofi one board or plank after the other and deliver them to the sorting table chains. In pickin oil the boards the apparatus is adjusted eit er automatically or by hand to maintain a constant angular relation of the pick 03 chains at the pick oif point as layer after layer of planks is removed.

The apparatus to carry out the operations described may assume many forms, tho but one form is shown in the accompanying.

drawings.

.We wish it understood however that we do not limit ourselves to this one form but.

wish to include in our claims any apparatus which will function as described'to carry I out our method of unstackin'g.

In the drawings, Figure lis a'side'ele'va lumber unit I tion of our unstacker with a in delivered to the tipping arms. igure 2 is a plan View of igu ping arms with a unit in place therein, and also shows the pick ofi chains in their rela tion to the arms.

Figure 4 is a still larger off chains in relation to the edges of planks being picked ofi of the unit.

Figures 5, 6, and 7 are structural sections detail. a the pick the .unit being an obtuse angle,

m1. Fi ure 3 is an enlarged side elevation of the tip'-' of Figure 3 along similarly numbered sectional indicia Figures 8 and 9 are, respectively, side elevatlon and plan views of the tipping arms and pick oif elements showing additional adustment to the latter for controllingethe picking angle. a A

Figure 10 is a section ofFigure 8 along the line indicated thereon. I

y In further detail the figures show at 1 the lumber units being conveyed ona chain or other receiving conveyor 2 to the tipping arms 3, which latter are spaced along a revolvable shaft l.

The units can beadvanced one at a time into the arms 3 as best indicated in Figure 8 at A and then by partial revolution of the arms dumped over to the position B.

When in position B down edgewise until they bear against the upper edges of the supporting advance arm as shown, and at which time the pick ofl chains 5 extending adjacent the unit at a slightly different angle than the lower edges of theboards, pick off the forward boards one at a time, layer after layer, and pass the boards up an incline to the-sorting table or conveyor chains 6.

The picking ofl of the boards is effected by the nu s or enlargements at the points of articulation of thechains as illustrated in Figure 4 and where it will be observed that the lower edges of: the. boards 1 present a stepped arrangement to the chains so that the advance board 1 is easily nubbed from the unit. This stepped arrangement'of the board edges is due to the angle of the cooperating edges of the arms embracing the obtuse the angle the more pronounced are the steps.

The angle between any two sets of arms is made obtuse by the arms being much wider at the hub portion than at the extremities, and if desired the angle maybe further increased by using of four. I

.The boards fall by gravity as the lower one is picked OE, and after the picking chains have picked off the first layer of boards it is manifest that the chains must approach closer to the unit in order to pick off the next layer, and also that the chains must not approach too close so as to forcibly pick off two layers instead of one. This is easily done by three sets of arms instead the planks all slide and the more one of several, or a combination of several means, either the tipping arms 3 may be slowly advanced by power or hand at a speed which will give the pick off chains time enough to clear layer after layer of boards without choking or overlapping, or, in addition or instead of this the pick off chains may also be carried on swinging arms 7 and raised gradually as the boards are removed.

The mechanism for moving the tipping arms 3 as described is shown in Figures 1 and 2, and the additional mechanism for moving the swinging arms 7 is illustrated in Figures 8 and 9. 1

In still further detail it will be vobserved that the shaft- 4 which carries the tipping I arms also serves as a support or bearing for i by the worm the head sprockets 8 forthe receiving conveyor 2 and whichsprockets are secured to driving sprockets-9 so that both will idle together on the shaft, and the sprockets 9 are drivenby chains 10 from sprockets 11 on a jack shaft 12 geared through reduction gears 13 extending beneath the mill floor 14 to driving elements carried under the fioor including a pair of spur frictions 15 driven by belting 16 from one side of a motor 17, while from the other side of" the motor a belt 18 drives a set of reversing frictions 19 suitably geared down to a worm shaft 20 carrying a worm 21 meshing with a worm wheel '22 secured to the tipping arm shaft 4 for revolving the arms. The. worm shaft also extends to a pair of bevel gears 23 connecting a vertical shaft 24 extending above the floor and topped with a handwheel 25.

A pair of hand levers 26 and 27 also extend through the floor adjacent the handwheel whereby the spur frictions 15 can be engaged or disen aged to operate the receiv ing conveyor and bring a fresh unit to the exact position required to properly enter the receiving set of tipping arms and also the reversing. frictions 19 can be selectively engaged to either advance or reverse the arms,-it bein understood that tho the armsnormally revo ve to the right, it is just as feasible to reverse the arms to pick up the fresh unit by the same arms just emptied of a unit by the pick off chains, and in which case of course the shaft never makes a complete revolution and therefore but two arms pould be required on each spider instead of 1 our.

When the shaft is revolved the arms pass through slots inthe floor as indicated, and just forward of the shaft is a large opening 28 through the floor to permit, the stickers? of stuck units tofall to a lower level for there assembling for re-us'ing.

From thejdrive shown it will be seen that the tipping arms: are locked in any position i)and also that the arms may be advanced power to the picking position, then furt er advanced by! power or by oil of the boards.

If power is used to control the picking it is desirable that the speed of travel of the arms be reduced to keep within the capacity of the pick off chains as suggested, and this may be done'either with an extra reduction gear introduced at some point in the transmission, or better by a variable speed motor controlled by the switch 29 t rough the wiring 29.

The sorting conveyor chains are driven by any available source of power delivered to the'head shaft of the conveyor at the other ,end, not shown in the drawings, and on the -tail shaft 30 are sprockets 31 connected by chains 32 to sprockets 33 to the head shaft 36 of the-pick ofi' chain conveyor and whereby the pick oif chains operate continuously with the sorting conveyor.

The pick off chains are supported in suitable channel tracks 34 as shown in Figures '5 and 6, and at the discharge end of the chains are inclined blocks 35 for delivering the boards 1 gently to the sorting conveyor,

tho of course this may also be accomplished by lowering the pick off chain head sprockets 37 on their shaft 36.

The tail sprockets 38 for the pick off chains idle on the tipping arm shaft, and the picking chain angle is maintained by thechannel-iron guides 34, and which are gently curved to discharge the boards to the sorting conveyoras shown.

Instead of the channels being fixed they may be carried on pivoted or swinging arms 7 as shown in Figures 8 and 9 having sprockets at'opposite ends and driven directly from the sorting conveyor tail shaft 30. The swinging arms 7 each have a connecting rod 39 extending to a crank 40 on shaft 41 and may be raised gradually to pick off the power throu h sliding of the friction-s secured to sha t 47, which in turn is suitably geared at 48 to the shaft 45.

arms 7 and rods 39 is shown.

With this quadruple control as described, -for picking off the'boards, (hand or power at the tipping arms, andhand or power at the pick off chains) every provision for con- In Figure 10 the sectional construction of trollin the operation from either point is assure and while we have shown and menf tionecl chains and cha n conveyors through out this specification it is evident without illustration that any equivalents such as belts, or cables, slatted or otherwise nubbed, cable conveyors, rolling conveyors, or any of the various well known forms of such devices may be interchanged with those shown to carry out our method of unstacking, and We feel entitled to the exclusive rights to the use of any such combinations to effect our urpose, and also to an method of tipping t e units whereby the oards become available for gravitational delivery of successive boards or successive layers of boards, and therefore we claim as our invention.

Claims 1. In a lumber unstacker of the character described, two sets of spider arms projecting radially from a common shaft, said sets of arms being arranged to embrace between the sets an obtuse angle for support of a lumber unit against'both sets of arms and whereby the supported sides of the unit will form the same obtuse angle and the edges of the boards of the unit will become in stepped relation, one to the other.

' 2. In an apparatus of the character described, means for tipping a lumber unit at an angle, and means for successively nubbing the boards therefrom comprising a device having nubs adapted toengage the edge of each board in succession.

3. In an apparatus of the character described, means Ior stepping the edges of the boards in a lumber unit, and means for removing the boards consecutively by engaging them at their stepped ed es.

4. In an apparatus of the character described, atipping device adapted to support a lumber unit, means for depositing a lumber unit therein, means for tipping the device with the unit therein, and means for removing the boards from one of the slanted sides of the tipped unit.

5.. In a structure as defined in claim 4, said last mentioned means comprisng a traveling conveyor running adjacent the slanted side and adapted to remove the boards therefrom consecutively.

6. In an apparatus of the character described, means for stepping the edges of the boards in a lumber unit comprising a travelling conveyor ,running adjacent the slanted side of the unit and having portions adapted to, consecutively rub off the boards from the slanted side for the purpose specified.

7. In an apparatus of the character de- I.

.. port.

scribed, means for picking off the boards from the side of an angularly placed lumber unit, comprising a plurality of conveyorv elements adapted to be brought into successive engagement with each board While traveling at an angle to their edges and sides.

8. In an apparatus of the character described, means for picking off the boards from the slanted side of an angularly placed lumber unit, comprising a plurality of conveying elements adapted to be brought into successive engagement with each board while traveling at an angle to their edges and sides, and means for adjusting the angular position of the conveying elements. to and from the edges of the boards.

9. In an apparatus of the character described, means for picking off the boards from the slanted side of an angularly placed lumber unit, comprising a plurality of conveying elements adapted to be brought into contact with the boards atan angle to their edges, and means for altering the angular relation of the conveying elements to the edges of the boards.

10. In an apparatus of the character described, a horizontall disposed shaft, a plurality of sets of spid iar arms secured thereto, said arms being adapted to pick up with one set of arms a lumber unit placed against them transversely of the arms at one side of the shaft and carry the unit over the shaft transferring the weight of the unit to another set of arms, and means for actuating said shaft to-move the arms in either direction of rotation.

' 11. In a structure as defined in .claim 10,

the last mentioned means including a wormwheel secured to the shaft, a worm meshing therewith, a revolvable shaft secured to the worm, and means for actuating the latter shaft by power from one point, and by hand from another point for minute control.

12. In an apparatus of the character de- 13. In a lumber unstacker of the character described, two sets of arms pivotally supported and arranged to embrace between the sets an obtuse angle and adapted to hold a shifting from one set of arms to the other 'llU lumber unit within the-obtuse angle for upon moving the arms on their pivotal-sup- JAMES M. LEAVER. JAMES M. LEAVER, JR. 

